Quoting John Stultz (2020-07-10 15:44:18)
> On Thu, Jul 9, 2020 at 11:02 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
> >
> > Does it work? I haven't looked in detail but I worry that the child
> > irqdomain (i.e. pinctrl-msm) would need to delay probing until this
> > parent irqdomain is registered. Or has the hierarchical irqdomain code
> > been updated to handle the parent child relationship and wait for things
> > to probe or be loaded?
>
> So I can't say I know the underlying hardware particularly well, but
> I've been using this successfully on the Dragonboard 845c with both
> static builds as well as module enabled builds.
> And the same patch has been in the android-mainline and android-5.4
> kernels for a while without objections from QCOM.
>
> As to the probe ordering question, Saravana can maybe speak in more
> detail if it's involved in this case but the fw_devlink code has
> addressed many of these sorts of ordering issues.
> However, I'm not sure if I'm lucking into the right probe order, as we
> have been able to boot android-mainline w/ both fw_devlink=on and
> fw_devlink=off (though in the =off case, we need
> deferred_probe_timeout=30 to give us a bit more time for modules to
> load after init starts).
>
Ok I looked at the code (sorry for not checking earlier) and I see this in
msm_gpio_init()
np = of_parse_phandle(pctrl->dev->of_node, "wakeup-parent", 0);
if (np) {
chip->irq.parent_domain = irq_find_matching_host(np,
DOMAIN_BUS_WAKEUP);
of_node_put(np);
if (!chip->irq.parent_domain)
return -EPROBE_DEFER;
so it looks like we'll probe defer the pinctrl driver until the pdc module
loads. Meaning it should work to have pinctrl builtin and pdc as a module.
